SPECIAL NEWS 2

NASA Spacecraft Closes in on Comet Tempel 1

"For the first time, we'll see the same comet before and after its
closest approach to the sun," explains Joe Veverka, principal
investigator for NASA's Stardust-NExT mission.

The comet is Tempel 1, which NASA's Deep Impact probe visited in
2005. Now another NASA spacecraft, Stardust-NExT, is closing in for a
second look on Valentine's Day, Feb. 14, 2011. The two visits bracket
one complete orbit of the comet around the sun--and a blast of solar
heat.

"Close encounters with the sun never go well for a comet," says
Veverka. "Fierce solar heat vaporizes the ices in the comet's core,
causing it to spit dust and spout gas. The cyclic loss of material
eventually leads to its demise."

Researchers suspect the flamboyant decay doesn't happen evenly all
over a comet's surface*, but until now they've lacked a way to document
where, exactly, it does occur. Stardust NExT will image some of the
same surface areas Deep Impact photographed 6 years ago, revealing how
these areas have changed and where material has been lost.

At a January 2011 press conference, Veverka and other
Stardust-NExT team members listed the features they're most interested
in seeing again:

For starters, parts of the comet's surface are layered like pancakes.

"Earth has layers because water and wind move dirt and debris
around here, but layering on a comet was a surprise – and a mystery,"
says Veverka.

Pancake-layers and a possible powdery flow are among the surface
features of interest highlighted in this July 4, 2005, Deep Impact
photo of Comet Tempel 1. The bright flash is where Deep Impact dropped
an 820 lb copper projectile onto the comet. Stardust-NExT could get a
first look at the aftermath of the blast. [more]

"One idea is that two protocometary bodies collided at low speeds
and smushed together to form something like a stack of flapjacks," says
Pete Shultz, Stardust-NExT co-investigator.

Is that right? Data obtained by Stardust-NExT will provide clues and possibly reveal what made the "comet pancakes."

Another area intrigues the research team even more.

"There's a large plateau that looks like a flow," says Shultz. "If
it really is a flow, it means there was recently gas and dust emanating
from the [surface]."

Stardust-NExT will reveal how the plateau has changed (Is it
flowing?), helping the team determine its origin. Whatever their origin,
the plateau and layering show that comets have a much more complicated
geologic history than previously thought.

It's a history NASA has had a hand in. During its 2005 visit, Deep
Impact dropped an 820-pound projectile into the comet's core. In a
development that surprised mission scientists, the impact excavated so
much material that the underlying crater was hidden from view. Deep
Impact's cameras were unable to see through the enormous cloud of dust
the impactor had stirred up. Stardust NExT could provide a long
anticipated look at the impact site.

"The dust has settled there, so if the right part of the comet is
facing us, we could see the crater and learn its size," says Veverka.
"That would answer some key questions. For instance, is a comet's
surface hard or soft?"

In a future mission, a spacecraft may land on a comet and gather
samples for analysis. To design a suitable lander, researchers need to
know what kind of surface it would land on. They'll also need to know
which tools to send – drills for hard surfaces or scoops for something
softer.

Like Deep Impact, the Stardust spacecraft has already had a
productive career. Launched in 1999, it approached Comet Wild 2 close
enough in 2004 to image its feature-rich surface and even gather dust
particles from the comet's atmosphere. (A key finding in the sample was
the amino acid glycene – a building block of life.)

"We could have just let this old spacecraft rest on those laurels,
leaving it to forever orbit the sun," says Veverka. "But instead, we're
doing first-class comet science with it -- again."

*Scientists estimate that a comet's surface is diminished
an average of 5 to 6 feet of during each "date" with the sun, and the
loss is not uniform. "Typically only 10 to 20 percent of a comet's
surface is active, so those areas could lose as much as 50 to 60 feet,"
explains Veverka. "That means comets are not uniform on the inside
either – some places are icier, some rockier."

NASA' SOLAR STEREO - A & STEREO - B SATELLITES IN SLIGHTLY DIFFERENT ORBITS AROUND THE SUN HAVE SEPARATEDTO BE PRECISELY OPPOSITE THE SUN ON 2011 FEB 6 ABOUT 7:30 PM EST - NEAR SUPERBOWL HALF-TIME.NASA WILL THEN RELEASE TO THE WORLD THE FIRST PICTURE EVER TAKEN OF THE ENTIRE SUN 360* AROUND(from these two satellites) - YOU CAN LOOK FOR YOURSELF AT THE STEREO WEBSITE FOR UPDATES WHICH IS:

The solar sphere as observed by STEREO and the Solar Dynamics
Observatory on January 31, 2011. Because the STEREO separation was still
slightly less than 180o at that time, a narrow gap on the far side of the Sun has been interpolated to simulate the full 360o view. The gap and quality of farside imaging will improve even more in the days and weeks ahead. [YouTube video] [full 42MB movie]

"This is a big moment in solar physics," says Vourlidas. "STEREO
has revealed the sun as it really is--a sphere of hot plasma and
intricately woven magnetic fields."

Each STEREO probe photographs half of the star and beams the
images to Earth. Researchers combine the two views to create a sphere.
These aren't just regular pictures, however. STEREO's telescopes are
tuned to four wavelengths of extreme ultraviolet radiation selected to
trace key aspects of solar activity such as flares, tsunamis and
magnetic filaments. Nothing escapes their attention.

"With data like these, we can fly around the sun to see what's
happening over the horizon—without ever leaving our desks," says STEREO
program scientist Lika Guhathakurta at NASA headquarters. "This could
lead to significant advances in solar physics and space weather
forecasting."

Consider the following: In the past, an active sunspot could
emerge on the far side of the sun completely hidden from Earth. Then,
the sun's rotation could turn that region toward our planet, spitting
flares and clouds of plasma, with little warning.

NOAA is already using 3D STEREO models of CMEs (billion-ton clouds
of plasma ejected by the sun) to improve space weather forecasts for
airlines, power companies, satellite operators, and other customers. The
full sun view should improve those forecasts even more.

The forecasting benefits aren't limited to Earth.

"With this nice global model, we can now track solar storms
heading toward other planets, too," points out Guhathakurta. "This is
important for NASA missions to Mercury, Mars, asteroids … you name it."

NASA has been building toward this moment since Oct. 2006 when the
STEREO probes left Earth, split up, and headed for positions on
opposite sides of the sun (movie).
Feb. 6, 2011, was the date of "opposition"—i.e., when STEREO-A and -B
were 180 degrees apart, each looking down on a different hemisphere.
NASA's Earth-orbiting Solar Dynamics Observatory is also monitoring the
sun 24/7. Working together, the STEREO-SDO fleet should

be able to image
the entire globe for the next 8 years.

The new view could reveal connections previously overlooked. For
instance, researchers have long suspected that solar activity can "go
global," with eruptions on opposite sides of the sun triggering and
feeding off of one another. Now they can actually study the phenomenon.
The Great Eruption
of August 2010 engulfed about 2/3rd of the stellar surface with dozens
of mutually interacting flares, shock waves, and reverberating
filaments. Much of the action was hidden from Earth, but plainly visible
to the STEREO-SDO fleet.

Positions of STEREO A and B for 6-Feb-2011 11:00 UT

This figure plots the current positions of the STEREO Ahead (red) and Behind
(blue) spacecraft relative to the Sun (yellow) andEarth(green). The dotted
lines show the angular displacement from the Sun. Units are in Astronomical Units (A.U)

1 AU = 92,955,807 Miles = The Average Earth-Sun Distance.

When the two spacecraft are close to Earth, an expanded view of the region
around Earth will appear on the right, in the same orientation as the
Sun-centered view.

NASA Robot and First Whole Sun Picture .. Coming on Super Bowl SUNday

by Ken Kremer on February 5, 2011

On
Super SUNday Feb. 6, 2011, NASA will release humankinds first ever
view of the entire Sun and NASA’s Robonaut 2 will make a first ever
guest appearance on the NFL’s Super Bowl Pre game show for Super
Bowl XLV.

Left: The Sun from STEREO taken by the SECCHI Extreme
Ultraviolet Imager (EUVI) at the 304 Angstrom bandpass which is
sensitive to the He II singly ionized state of helium, at a
characteristic temperature of about 80 thousand degrees Kelvin. Credit:
NASA.

The unlikely pairing of Football and Science
face off head to head on Super Bowl SUNday. Millions of television
viewers will see NASA’s Robonaut 2, or R2, share the the limelight with
the Steelers and the Packers of the NFL. The twin brother of R2 is
destined for the International Space Station (ISS) and will become the first humanoid robot in space. It will work side by side as an astronaut’s assistant aboard the space station.

The
fearsome looking R2 is set to make a first ever special guest
appearance during the FOX Networks Super Bowl pre-game show with FOX
sports analyst Howie Long.

The pre-game show will air starting at 2
p.m. EST on Feb. 6.

And there’s more.

The Sun from Stereo B.

Credit: NASA

On Super SUNday
Feb. 6, NASA will publish Humankinds first ever image of the ‘Entire
Sun’ courtesy of NASA’s twin STEREO spacecraft. And given the
stunningly cold and snowy weather in Dallas, the arrival of our Sun can’t come soon enough for the ice covered stadium and football fans. See photos above and below.

The two STEREO spacecraft will reach positions on opposite sides of the Sun on Sunday, Feb. 6 at about 7:30 p.m. in the evening, possibly coinciding with the Super Bowl half time show.

At
opposition, the STEREO duo will observe the entire 360 degrees sphere
of the Sun’s surface and atmosphere for the first time in the history of
humankind.

The nearly identical twin brother of R2 is packed
aboard Space Shuttle Discovery and awaiting an out of this world
adventure from Launch Pad 39 A at NASA’s Kennedy Space Center (KSC) in
Florida. Blast off of the first humanoid robot is currently slated for Feb. 24.

R2
is the most dextrously advanced humanoid robot in the world and the
culmination of five decades of wide-ranging robotics research at NASA
and General Motors (GM).

This newest generation of Robonauts are
an engineering marvel and can accomplish real work with exceptionally
dexterous hands and an opposable thumb. R2 will contribute to the
assembly, maintenance and scientific output of the ISS

The
amazingly dexterity of the jointed arms and hands enables R2 to use
exactly the same tools as the astronauts and thereby eliminates the need
for constructing specialized tools for the robots –saving valuable
time, money and weight.

R2 weighs some 300 pounds and
was manufactured from nickel-plated carbon fiber and aluminum. It is
equipped with two human like arms and two hands as well as four visible
light cameras that provide stereo vision with twice the resolution of
high definition TV.

“With R2 we will demonstrate ground breaking
and innovative robotics technology which is beyond anything else out
there and that will also have real world applications as GM works to
build better, smarter and safer cars,” according to Susan Smyth, GM
Director of Research and Development.

“Crash avoidance technology
with advanced sensors is a prime example of robonaut technology that
will be integrated into GM vehicles and manufacturing processes.”

A
team of engineers and scientists from NASA and GM pooled resources in a
joint endeavor to create Robonaut 2, the most dexterously advanced
robot in history. The NASA/GM team is pictured here at the Kennedy
Space Center. R2 will fly aboard Space Shuttle Discovery with the
STS-133 crew of humans and become the first humanoid robot in space. R2
will become an official ISS crew member. Credit: Ken Kremer

I
was fortunate to meet R2 and the Robonaut team at KSC. R2 is
incredibly life like and imposing and I’ll never forget the chance to
shake hands. Although its motions, sounds, illuminated hands and
muscular chest gives the unmistakable impression of standing next to a
lively and powerful 300 pound gorilla, it firmly but gently grasped my
hand in friendship – unlike a Terminator.

So its going to make for a mighty match up some day between the fearsome looking R2 and the NFL players.

Well
apparently, R2 and Howie will be making some predictions on which
player will win the MVP award and a GM Chevrolet. Stay tuned.

So come back on SUNday Feb. 6 for NASA’s release of the first ever images of our entire Sun from the STEREO twins.

Clash of the Titans - R2 and NASA robotics engineer at football practice at KSC. Credit: Ken Kremer

Space
Shuttle Discovery awaits launch from Pad 39 A at the Kennedy Space
Center, Florida. Robonaut 2 is loaded inside the Leonardo storage module
which will be permanently attached to the ISS by the STS-133 crew. Launch is now scheduled for Feb 24th.

Credit: Ken Kremer

On Super Bowl SUNday - Feb 6, 2011 - the Two NASA STEREO Spacecraft Will See the Entire Sun for the First Time Ever! Credit: NASA.

R2
has no lower half, yet weighs 300lbs. IMHO this is yet another case in
the world’s space program of throwing good money after bad. It will cost
a mint to get him up there, in money and pollution, just so he can tool
around with a Rubik cube or some such, giving engineers data they could
have got in the lab.

The space/astronaut program is now
degenerate – thank goodness for Planck, Herschel, Hubble, SDO etc.,
drawing attention away from this zero gravity nonsense.

NASA Probe (EPOXI) Delivers Dazzling Portraits of a Comet Aglow

Deep Impact takes thousands of pictures during
flyby

Multiple jets of gas flare from Comet
Hartley 2's nucleus, in a picture taken by NASA's Deep Impact/EPOXI
spacecraft during a flyby.

By Mike Wall

Space.com

updated
11/4/2010
2:35:23 PM ET2010-11-04T18:35:23

A NASA spacecraft has beamed back the first close-up photos from
its rendezvous with a comet — and the images show an ice ball that
looks like a giant chicken drumstick, or perhaps a peanut or bowling
pin.

Deep Impact (renamed EPOXI) zoomed to within 435 miles (700 kilometers) of Comet
Hartley 2 at 10:01 a.m. ET Thursday, and the probe beamed down its first
close-up shots an hour later. [
First close-up photos of Comet Hartley 2.]

Cheers erupted in the Mission Control room of NASA's Jet Propulsion
Laboratory as five high-resolution images of the mile-wide
(1.6-kilometer-wide) comet flashed up on a big screen. [
Another photo of Comet Hartley 2.]

Mission scientists hope the data gained during the rendezvous will
reveal what Hartley 2's icy nucleus is made of. By comparing Hartley 2
to the four other comets spacecraft have visited, they're hoping to gain
a better understanding of comet structure and behavior, and perhaps of
the solar system's formation.

"This comet is unlike any we've visited before, and we don't know
what we're going to find," Mike A'Hearn of the University of Maryland,
principal investigator of Deep Impact's mission, said before the
encounter.

During the encounter, the spacecraft was programmed to snap about
118,000 images, NASA officials said.

A long road to Hartley 2
The $252 million Deep Impact spacecraft took a circuitous
route to Comet Hartley 2.

NASA launched the current spacecraft in 2005 to serve as a mother
ship for the Deep Impact mission, which intentionally sent an impactor
probe
crashing into Comet Tempel 1 in July 2005 to study the
object's composition.

After that mission ended, NASA decided to squeeze some more life out
of the Deep Impact observer spacecraft. They planned to send it after a
comet named Boethin, aiming for a close flyby in December 2008. But that
didn't pan out because Boethin vanished, likely breaking up into many
tiny pieces.

So researchers settled instead on Comet Hartley 2, a small ice ball
that makes a long, looping trip around the sun once every 6 years. The
comet
was discovered in 1986 by Australian astronomer Malcolm
Hartley.

On June 27 of this year, Deep Impact whipped past Earth, using our
planet's gravity to set it on a course for Hartley 2. The extended
mission to rendezvous with Comet Hartley 2 costs about $42 million, NASA
says.

In September, Deep Impact went into approach mode as it neared its
icy target, taking pictures and gathering data to prepare for the flyby.
It switched to encounter mode on Wednesday. Deep Impact locked its
instruments two telescopes with digital color cameras and an infrared
spectrometer on Hartley 2, and the data started pouring in.

Deep Impact will continue photographing Comet Hartley 2 for about
three weeks as the comet speeds off into the dark reaches of space.
After that point, the spacecraft's comet-watching mission will be
basically over, and Deep Impact will be decommissioned after a final
calibration run, NASA officials said.

The spacecraft can retire with its head held high, having delivered
on two separate comet-hunting missions, mission managers said.

"This is going to give us the most extensive observation of a comet
to date," said Tim Larson of NASA's Jet Propulsion Laboratory. Larson is
project manager of Deep Impact's mission to Hartley 2, which NASA calls
EPOXI.

Waiting for the data deluge
Data from the close approach will continue to download
through Saturday.

NASA's broad EPOXI mission has been using the recycled and repurposed
Deep Impact spacecraft to track and study various celestial objects.
The name "EPOXI" is derived from the mission's dual science
investigations the Extrasolar Planet Observation and Characterization
(EPOCh) and Deep Impact Extended Investigations (DIXI).

Video: Comet gets its close-up

Comet Snowstorm Engulfs Hartley 2

Nov. 18, 2010: NASA has just issued a travel
advisory for spacecraft: Watch out for Comet Hartley 2, it is
experiencing a significant winter snowstorm.

Deep Impact photographed the unexpected tempest when it flew past
the comet's nucleus on Nov. 4th at a distance of only 700 km (435
miles). At first, researchers only noticed the comet's hyperactive jets.
The icy nucleus is studded with them, flamboyantly spewing carbon
dioxide from dozens of sites. A closer look revealed an even greater
marvel, however. The space around the comet's core is glistening with
chunks of ice and snow, some of them possibly as large as a basketball.

"We've never seen anything like this before," says University of
Maryland professor Mike A'Hearn, principal investigator of Deep Impact's
EPOXI mission. "It really took us by surprise."

Before the flyby of Hartley 2, international spacecraft visited
four other comet cores—Halley, Borrelly, Wild 2, and Tempel 1. None was
surrounded by "comet snow." Tempel 1 is particularly telling because
Deep Impact itself performed the flyby. The very same high resolution,
high dynamic range cameras that recorded snow-chunks swirling around
Hartley 2 did not detect anything similar around Tempel 1.

"This is a genuinely new phenomenon," says science team member
Jessica Sunshine of the University of Maryland. "Comet Hartley 2 is not
like the other comets we've visited."

The 'snowstorm' occupies a roughly-spherical volume centered on
Hartley 2's spinning nucleus. The dumbbell-shaped nucleus, measuring
only 2 km from end to end, is tiny compared to the surrounding swarm.
"The ice cloud is a few tens of kilometers wide--and possibly much
larger than that," says A'Hearn. "We still don't know for sure how big
it is."

Data collected by Deep Impact's onboard infrared spectrometer show
without a doubt that the particles are made of frozen H2O,
i.e., ice. Chunks consist of micron-sized ice grains loosely stuck
together in clumps a few centimeters to a few tens of centimeters wide.

This plot compares the infrared spectra of particles surrounding
Comet Hartley 2 (black crosses) to spectra of pure water ice grains in
the laboratory (purple lines). Micron-sized grains provide the best
match. What it means: Hartley 2's snowballs are made of small bits of H20.

"If you held one in your hand you could easily crush it," says
Sunshine. "These comet snowballs are very fragile, similar in density
and fluffiness to high-mountain snow on Earth."

Even a fluffy snowball can cause problems, however, if it hits you
at 12 km/s (27,000 mph). That's how fast the Deep Impact probe was
screaming past the comet’s nucleus. An impact with one of Hartley 2's
icy chunks could have damaged the spacecraft and sent it tumbling,
unable to point antennas toward Earth to transmit data or ask for help.
Mission controllers might never have known what went wrong.

"Fortunately, we were out of harm's way," notes A'Hearn. "The snow
cloud does not appear to extend out to our encounter distance of 700
km. Sunlight sublimates the icy chunks before they can get that far away
from the nucleus."

The source of the comet-snow may be the very same garish jets that
first caught everyone's eye.

The process begins with dry ice in the comet's crust. Dry ice is
solid CO2, one of Hartley 2's more abundant substances. When
heat from the sun reaches a pocket of dry ice—poof!—it instantly
transforms from solid to vapor, forming a jet wherever local topography
happens to collimate the outrushing gas. Apparently, these CO2
jets are carrying chunks of snowy water ice along for the ride.

An artist's concept of Comet Hartley 2 shows how CO2
jets drag water ice out of nucleus, producing a 'comet snowstorm.' [larger
image]

Because the snow is driven by jets, "it's snowing up, not
down," notes science team member Peter Schultz of Brown University.

Ironically, flying by Hartley 2 might be more dangerous than
actually landing on it. The icy chunks are moving away from the comet’s
surface at only a few m/s (5 to 10 mph). A probe that matched velocity
with the comet's nucleus in preparation for landing wouldn't find the
drifting snowballs very dangerous at all--but a high-speed flyby is
another matter. This is something planners of future missions to active
comets like Hartley 2 will surely take into account.

Comet snowstorms could be just the first of many discoveries to
come. A’Hearn and Sunshine say the research team is only beginning to
analyze gigabytes of data beamed back from the encounter, and new
results could be only weeks or months away.

Earth's Dust Tail Points to Alien Planets

November 12, 2010: Did you know that the
Earth has a dust tail? The Spitzer Space Telescope sailed right through
it a few months ago, giving researchers a clear idea of what it looks
like. That could be a big help to planet hunters trying to track down
alien worlds.

"Planets in distant solar systems probably have similar dust
tails," says Spitzer project scientist Mike Werner. "And in some
circumstances these dust features may be easier to see than the planets
themselves. So we need to know how to recognize them."

It's extremely challenging – and usually impossible – to directly
image exoplanets. They're relatively small and faint, hiding in the
glare of the stars they orbit.

"A dust tail like Earth's could produce a bigger signal than a
planet does. And it could alert researchers to a planet too small to see
otherwise."

Earth has a dust tail not because the planet itself is
particularly dusty, but rather because the whole solar system is.
Interplanetary space is littered with dusty fragments of comets and
colliding asteroids. When Earth orbits through this dusty environment, a
tail forms in the rear, akin to swaths of fallen leaves swirling up
behind a streetsweeper.

"As Earth orbits the sun, it creates a sort of shell or depression
that dust particles fall into, creating a thickening of dust – the tail
– that Earth pulls along via gravity," explains Werner. "In fact, the
tail trails our planet all the way around the sun, forming a large dusty
ring."

Like our own solar system, other planetary systems are infused
with dust that forms a dusty disk encircling the central star. And like
Earth, exoplanets interact with their dust disk gravitationally,
channeling and drawing strange features into it.

"In some stars' dust disks there are bumps, warps, rings, and
offsets telling us that planets are interacting with the dust," explains
Mark Clampin of NASA's Goddard Space Flight Center. "So we can 'follow
the dust' to the planets. So far, we've seen about 20 dust disks in
other solar systems. And in some of those cases, following the dust has
already paid off."

Clampin, Paul Kalas, and colleagues were looking for a planet
around the bright southern star Fomalhaut when they unexpectedly found a
dust ring. The shape of that ring led them to their goal. "We suspected
that the ring's sharp inner edge was formed by a planet gravitationally
clearing out the surrounding debris," says Clampin. "We tracked the
planet by this 'footprint' in the dust." (See the footprint
here.)

Another Hubble image shows a dusty disk around Beta Pictoris, a
star in the constellation Pictor, or "Painter's Easel," pictured below:

"Note the smaller dust ring that's tilted with respect to the
larger dust disk," says Clampin. "Like Earth, this planet is shepherding
the dust into its orbital plane."

Clampin and Werner say Spitzer's observation of Earth's dust tail
and these initial observations of dust structures in distant solar
systems set the stage for the planet hunting debut of the James Webb
Space Telescope. They fully expect the huge and powerful new telescope
to spot many tell-tale tails ... of the alien variety.

(1) Clampin explains why it's hard to see the Earth's dust
tail from within our solar system: "Imagine looking at fog on the Golden
gate from above where you can clearly see the structure. If, on the
other hand, you are standing on the bridge, it's a lot harder to discern
the shape of the cloud."

(2) NASA's James Webb Space Telescope, targeted to launch in
2015, is a large, infrared-optimized space telescope. For more
information, see http://www.jwst.nasa.gov/

All the things in the universe that we can easily see — stars, nebulae,
and so on — amount to less than 1% of all the matter and energy that's
known to be out there.

The
basic ingredients of the universe; everything else is detail. Normal, or
baryonic matter — the building blocks of atoms and molecules —
accounts for 4.6% of all matter and energy. A lot of even this went
unseen until recently.

Sky & Telescope

"Dark matter" and "dark energy" account for 95.4% of everything,
judging by many lines of converging evidence (see the June Sky &
Telescope, page 14). But that still leaves 4.6% of everything as
“ordinary” matter: material made of protons, neutrons, and electrons,
the stuff of atoms. Until recent years, astronomers could only tally up
about half as much ordinary matter as cosmologists said there ought to
be, judging from the state of the universe soon after the Big Bang.

Now
the mystery seems solved. In recent years astronomers had already found
signs that the missing ordinary matter indeed exists, as a thin,
elusive gas between galaxies known as the “warm-hot intergalactic
medium,” or WHIM.

The evidence for WHIM has now turned firmer.
Its signature showed up (weakly) in a spectrum of X-rays arriving from a
distant source. Absorption lines revealing WHIM were imprinted on the
X-rays where they passed through the Fornax Wall, an enormous structure
of thousands of galaxies in the vast web of galaxy strings, walls, and
clusters pervading the cosmos.

In this artist's
illustration, X-rays from a background source (narrow beam) pass through
the Fornax Wall of galaxies and thin intergalactic gas (blue fuzz) on
their way to Earth.

NASA / CXC / M.Weiss

The spectral signature matches both the predicted amount and
temperature (about 1 million kelvins) of the elusive intergalactic gas.
One reason it has gone unseen is that it is very sparse: there's only
about 6 hydrogen atoms' worth per cubic meter, compared with the 1
million atoms per cubic meter that's typical of the interstellar
gas within galaxies.

As mysterious as ever is the nonbaryonic
dark matter: the 22% of the cosmic inventory that is matter but
is not made of protons, neutrons, and electrons.

An
international team unveiled the origin of the giant gas ring in the Leo group of galaxies. With the
Canada-France-Hawaii Telescope, the
scientists were able to detect an optical signature of the ring
corresponding to star forming regions.
This observation rules out the primordial nature of the gas, which is of
galactic origin. Thanks
to numerical simulations made at CEA, a scenario for the formation of
this ring has been proposed: a violent collision between two galaxies,
slightly more than one billion years ago. The results will be published
in the Astrophysical Journal Letters.

In the current theories on galaxy formation, the
accretion of cold primordial gas is a key-process in the early steps of galaxy growth. This
primordial gas is characterized by two main features: it has never
sojourned in any galaxy and it does not satisfy the conditions required
to form stars. Is such an
accretion process still ongoing in nearby galaxies? To answer the
question, large sky surveys are undertaken attempting to detect the
primordial gas.

The Leo ring, a giant ring of cold gas 650,000
light-years wide surrounding the galaxies of the Leo group, is one of
the most dramatic and mysterious clouds of intergalactic gas.
Since its discovery in the 80s, its origin and its nature were debated.
Last year, studies of the metal abundances in the gas led to the belief
that the ring was made of this famous primordial gas.

Thanks to
the sensitivity of the Canada-France-Hawaii Telescope MegaCam camera,
the international team observed for the first time the optical
counterpart of the densest regions of the ring, in visible light instead
of radio waves. Emitted by massive young stars, this light
points to the fact that the ring gas is able to form stars.

A
ring of gas and stars surrounding a galaxy immediately suggests another
kind of ring: a so-called collisional ring, formed when two galaxies
collide. Such a ring is seen in the famous Cartwheel galaxy. Would the
Leo ring be a collisional ring too?

In order to secure this
hypothesis, the team used numerical simulations (performed on
supercomputers at CEA) to demonstrate that the ring was indeed the
result of a giant collision between two galaxies more than 38 million
light-years apart: at the time of the collision, the disk of gas of one
of the galaxies is blown away and will eventually form a ring outside of
the galaxy. The simulations allowed the identification of the two
galaxies which collided: NGC 3384, one of the galaxies at the center of
the Leo group, and M96, a massive spiral galaxy at the
periphery of the group. They also gave the date of the collision: more
than a billion years ago!

The gas in the Leo ring is definitely
not primordial. The hunt for primordial gas is still open!

A Response to
“Mysterious Giant Gas Ring Explained”

Yeah, their has been
a lot of debate on the age of this object since it was first discovered
by radio astronomers in the 1980's. A few years back, observations by
the GALEX observatory detected a few clumps of very young stars in the
Leo Ring. Primordial gas proponents claimed that these were the first
stars to form from gas in the ring since the Big Bang. But these new
observations cast doubt on the primordial nature of this feature. The
paper, "A collisional origin for the Leo ring" can be found here: http://arxiv.org/PS_cache/arxiv/pdf/1005/1005.4208v2.pdf

Obama Pledges 2025
Mission to Asteroid

WASHINGTON — Pledging to
send astronauts to an asteroid by 2025, U.S. President Barack Obama
defended
his decision to pull the plug on NASA’s proposed return to the Moon,
saying the
new course he is setting for the U.S. space agency promises to take
people beyond Earth orbit farther and faster than the old plan.

“I understand that some believe we should attempt a return
to the surface of the Moon first, as previously planned,” Obama told an
invitation-only
audience in an April 15 speech at NASA’s Kennedy
Space Center
in Florida.
“But I just have to say pretty bluntly here. We’ve been there before.
...
There’s a lot more of space to explore, and a lot more to learn when we
do. So
I believe it’s more important to ramp up our capabilities to reach and
operate
at a series of increasingly demanding targets while advancing our
technological
capabilities with each step forward. And that’s what this strategy does.
And
that’s how we will ensure that our leadership in space is even stronger
in this
new century than it was in the last.”

Obama’s 2011 budget request, submitted to Congress in
February, proposes the cancellation of the Moon-bound Constellation
program in
favor of extending NASA’s support of the international space station
through at
least 2020 and investing in “game-changing” technologies aimed at
speeding the
human and robotic exploration of deep space. Obama’s initiative also
puts a
strong emphasis on relying on an emerging commercial space sector for
launching
astronauts and their gear to the international space station.

Obama said that under his plan, U.S. astronauts will venture beyond
Earth’s orbit in 2025, starting with a crewed mission to an asteroid.

“Early in the next decade a set of crewed flights will test
and prove the systems required for exploration beyond low Earth orbit,”
he
said. “And by 2025 we expect new spacecraft designed for long journeys
to allow
us to begin the first ever crewed missions beyond the Moon into deep
space. So
we’ll start by sending astronauts to an asteroid for the first time in
history.”

Obama also gave a specific timeline for embarking on human
expeditions to Mars.

“By the mid-2030s I believe we can send humans to orbit Mars
and return them safely to Earth,” Obama said. “And a landing on Mars
will
follow, and I expect to be around to see it.”

Turning to jobs, Obama said his plan “will add more than
2,500 jobs along the [Florida] Space Coast
in the next two years compared to the plan under the previous
administration”
and more than 10,000 jobs nationwide. He also said he has asked for a
plan by
Aug. 15 for a $40 million initiative for economic growth and job
creation in
areas of Florida
expected to be hard hit by the looming retirement of the space shuttle.

Some key details of the president’s address were released by
the White House April 13, including a decision to continue development
of a
stripped-down version of the Orion Crew Exploration Vehicle to serve as a
crew
lifeboat at the international space station. The White House also said
NASA
will select by 2015 a design for a heavy-lift launcher that most experts
agree
is necessary for human exploration beyond low Earth orbit.

Explanation:
What is this strange object?
First discovered on ground based
LINEAR
images on 2010 January 6, the object appeared unusual
enough to investigate further with the
Hubble Space Telescope last week.
Pictured above, what Hubble saw indicates that P/2010 A2 is unlike any object ever seen before.
At first glance, the object appears to have the
tail of a comet.
Close inspection, however, shows a 140-meter
nucleus offset from the tail center, very unusual structure near the nucleus, and no discernablegas in the tail.
Knowing that the
object orbits in the
asteroid belt
between Mars and
Jupiter, a preliminary hypothesis that appears to explain all of the known clues is that
P/2010 A2
is the debris left over from a recent
collision
between two small asteroids.
If true,
the collision likely occurred at over 15,000 kilometers per hour -- five times the speed of a
rifle bullet--
and liberated energy in excess of a
nuclear bomb.
Pressure from sunlight would then spread out the debris into a trailing tail.
Future
study of P/2010 A2 may better indicate the nature of the progenitor collision and may help humanity better understand the
early years of our Solar System, when many similar collisions occurred.

Though the sun was so much dimmer billions of years ago that the
young Earth should have been literally freezing, the planet remained
largely covered with liquid water. That was thanks to a substantially
darker surface and a dearth of light-scattering clouds, a new study
suggests.

“All other things being equal, Earth should have been frozen over for
the first half of its existence,” says James F. Kasting, a geoscientist
at Pennsylvania State University in University Park who was not
involved in the research. “But it wasn’t.”

Previously scientists have explained the presence of liquid water
during that low-light time, known as the Archean, by suggesting that
Earth’s atmosphere held large amounts of planet-warming greenhouse gases
such as carbon dioxide and methane. But new analyses show that
greenhouse gases weren’t dramatically higher then compared with today, a
team of earth scientists reports in the April 1 Nature. The
researchers now propose that early Earth stayed above freezing because
the planet was darker then and therefore absorbed more of the sun’s
energy — the same phenomenon that renders dark vinyl car seats scorching
hot while light-colored seats stay relatively cool.

Early in the sun’s lifetime, the portion of solar core where the
light- and heat-generating fusion reactions take place was much smaller
than it is today. So, for an extended period, the sun could have been up
to 30 percent dimmer than it is now, says Minik Rosing, a geologist at
the University of Copenhagen’s Nordic Center for Earth Evolution.
Although Earth’s surface temperature should have been well below
freezing, geological signs of liquid water in that era abound — a
puzzler that scientists have dubbed the “faint young sun paradox.”

Some studies have suggested that carbon dioxide concentrations in
Earth’s early atmosphere were more than 100 times current levels. But
the new analyses of ancient rocks known as banded iron formations reveal
proportions of iron-bearing minerals that could appear only if carbon
dioxide levels were no more than three times modern values — a
concentration too low to keep the planet from freezing beneath a faint
young sun. Methane probably didn’t help make up the difference, Rosing
adds, because at high concentrations methane reacts chemically to form a
light-scattering haze that would have cooled Earth’s surface rather
than warming it.

What probably kept Earth above freezing during the dim-sun era was
its darker surface, Rosing and his colleagues contend. The continents
were much smaller then, so the planet’s oceans — which are typically
much darker than landmasses — could absorb more heat. About 3.8 billion
years ago, continents covered less than 5 percent of Earth’s surface, a
proportion that gradually rose to reach today’s value of 30 percent
around 1.5 billion years ago.

Second, the researchers suggest, light-scattering clouds covered much
less of Earth’s surface long ago — another net gain for surface warmth.
Because early Earth lacked plants and other complex life, the
biologically produced particles and chemicals that water droplets
coalesce around weren’t available. In the few clouds that did form,
droplets were larger and scattered light less efficiently, allowing more
warming radiation to reach ground level.

In their paper, the researchers present a numerical simulation that
shows how these two rather straightforward phenomena could have kept
Earth’s average temperature above freezing.

“A lot of the reviewers of our paper were kicking themselves and
asking, ‘Why didn’t we think of this first?’” Rosing notes.

Despite the new findings, the faint young sun problem may not be
fully solved, Kasting notes. For one thing, the new analyses don’t
consider the effect of high-latitude ice masses on the planet’s albedo.
“We clearly need additional constraints to understand why the Archean
Earth remained habitable,” he comments in Nature.

"This opens the door to a totally new era of discovery," the
project's director of research Sergio Bertolucci told news agencies. "It
is a step into the unknown where we will find things we thought were
there and perhaps things we didn't know existed."

The resulting collisions could produce evidence of types of
matter that physicists have theorized exist for decades, but have never
seen. That includes "dark matter," the hypothetical substance than some
scientists think makes up as much as 80 percent of the universe, and the
elusive Higgs Boson particle, the so-called "God
particle" scientists believe gives all other matter its weight.

The Large Hadron Collider has had problems and false starts over the
past few years, including an explosion and helium leak in 2008 that
caused a long delay. Today, though, the accelerator worked.

Beams of protons began circulating through the 17 miles of magnetic
tubes that traverse the French-Swiss border, gathering speed, Tuesday
morning. At 1:06 p.m. the beams collided, smashing into each other in a
7-trillion electron-volt collision.

In 2008, when the scientists first tested the collider by sending one
beam of particles through the tubes, physicist Brian Greene explained
on the NewsHour how the collider would work.

NOTE THAT THE INTERNATIONAL SUPERCONDUCTING SUPERCOLLIDER THAT WAS BEING BUILT IN TEXAS AND WAS SUDDENLY SUMMARILY CANCELLED BY THE US GOVERNMENT IN 1993 DUE TO COST (ALTHOUGH INTERNATIONAL CONTRIBUTIONS WERE STEADILY COMING IN) WOULD HAVE REACHED AN ASTOUNDING 40 TRILLION ELECTRON VOLT COLLISION CAPACITIES.

Contents

Development

The system was first envisioned in the December 1983 National
Reference Designs Study, which examined the technical and economic
feasibility of a machine with the design capacity of 20 TeV per beam.
After an extensive Department of Energy review during the mid-1980s, a
site selection process began in 1987. The project was awarded to Texas
in November 1988 and major construction began in 1991. Seventeen shafts
were sunk and 23.5 km (14.6 mi) of tunnel were bored by late 1993.

Cancellation

During the design and the first construction stage, a heated debate
ensued about the high cost of the project. In 1987, Congress was told
the project could be completed for $4.4 billion, and it gained the
enthusiastic support of SpeakerJim
Wright of nearby Fort Worth.[1]
By 1993, the cost projection exceeded $12 billion. A recurring argument
was the contrast with NASA's contribution to the International Space Station
(ISS), which was of a similar amount.[citation needed] Critics
of the project argued that the US could not afford both of them.

A high-level schematic of the lab landscape during the final planning
phases.

Congress canceled the project in
1993. Many factors contributed to the cancellation: rising cost
estimates; poor management by physicists and Department of Energy
officials; the end of the need to prove the supremacy of American
science with the collapse of the Soviet
Union; belief that many smaller scientific experiments of equal
merit could be funded for the same cost; Congress's desire to generally
reduce spending; the reluctance of Texas Governor Ann
Richards;[2]
and President Bill Clinton's initial lack of support for a
project begun during the administrations of Richards's predecessor, Bill
Clements, and Clinton's predecessors, Ronald
Reagan and George H. W. Bush. However, in 1993,
Clinton tried to prevent the cancellation by asking Congress to continue
"to support this important and challenging effort" through completion
because "abandoning the SSC at this point would signal that the United
States is compromising its position of leadership in basic science".[3]

The closing of the SSC had adverse consequences for the southern part
of the Dallas–Fort
Worth Metroplex, and resulted in a mild recession,
most evident in those parts of Dallas which lay south of the Trinity River.[4]
When the project was canceled, 22.5 km (14.0 mi) of tunnel and 17
shafts to the surface were already dug, and nearly two billion dollars
had already been spent on the massive facility.[5]

Comparison
to the Large Hadron Collider

The SSC's planned collision energy of 40 TeV was almost triple the 14 TeV of its European
counterpart, the Large Hadron Collider (LHC) at CERN in Geneva.
The LHC was less expensive to build because, in addition to its smaller
size, the LHC took over the existing engineering infrastructure and 27 km
long underground cavern of the Large
Electron-Positron Collider. The LHC eventually cost the equivalent
of about 5 billion US dollars to build.

Current Status of Site

Panoramic view of the SSC site

After the project was canceled, the main site was deeded to Ellis County, Texas, and the county tried numerous
times to sell the property. The property was finally sold in August 2006
to an investment group led by the late J.B. Hunt.[6]
Collider Data Center has contracted with GVA Cawley to market the site
as a tier III or tier IV data
center.[7]

Much later, after the hole in the roof had been fixed and the debris
cleaned up, after the cause of the damage finally had become clear,
Frank Ciampi wondered: What are the odds?

He is a doctor. He has worked for 18 years in the two-story building
in Lorton that houses the Williamsburg Square Family Practice, in the
9500 block of Richmond Highway. He spends his days walking in and out
of examining rooms, seeing patients.

What are the chances, as he goes about his routine, that he'll get hit by a meteorite?

Not impossible.

It almost happened.

"I was in my office doing charts," Ciampi recalled. It was Monday, a
little after 5:30 p.m. He was on the building's second floor. "And I
heard a loud boom, almost like a small explosion."

At first, he said, he thought a bookcase had toppled nextdoor. "So I
ran toward the office. And then I saw all the debris in the hallway,"
he said.

The floor just outside examination room No. 2 -- about 10 feet from
where Ciampi had been doing paperwork -- was littered with small pieces
of wood, plaster and insulation. Upon inspection, more debris lay
inside the room. He saw three chunks of stone on the floor that
together formed a rock about the size of a tennis ball, with a
glassy-smooth surface. Then he saw a hole about the size of the rock in
the tile ceiling, and a tear in the maroon carpet where the rock had
landed.

"The first thing we thought was maybe something had fallen from a plane," Ciampi said.

For most of the day, the 10 examination rooms used by Ciampi and two
other medical professionals in the practice had been occupied by
patients. Had the falling object crashed through the ceiling a little
earlier, it might have killed someone.

"I thank God," Ciampi said.

Later, he said, "I was up all night, wondering what it was." No one
else in the practice could figure it out, either. Then on Tuesday, the
office manager, Rhonda Lawrence, offered a suggestion from her husband
Jeffrey, who has a background in geology.

"Jeff said that maybe it was a meteorite," Ciampi said. "We didn't
think of that. You know, a meteorite -- that's not the first thing you
think of."

"The first thing we look at is what's called the fusion crust on the
outside," she said. "It's kind of a black, shiny coating, because when
it passes through the atmosphere, it's melting a little at a time. So
it's like an outer layer of glass, of melted rock."

That, plus flecks of metal in the rock, confirmed it had come from space, she said.

Corrigan said small meteorites hit Earth "fairly often." "We're
bombarded by stuff like that all the time," she said. Since most of the
planet's surface is uninhabited, most meteorites land a long, long way
from people. And most of those that do hit inhabited areas go
unnoticed, she said.

Every now and then, though, there's a landing like the one in
Lorton. She said the meteorite weighs just over a half pound and
probably was traveling about 220 mph when it hit the building.

If the folks at the medical practice want her to, Corrigan said, she
will submit the stone to the Meteorite Nomenclature Committee.

"They'll give it an official name and an official description and
it'll go on the books as being an official meteorite," she said. "I
would imagine it would be called the Lorton, Va., Meteorite, or
something like that."

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ON 2010 JANUARY 7 MARKED THE 400th ANNIVERSARY OF GALILEO's DISCOVERYOF JUPITER'S LARGEST MOONS THROUGH HIS CRUDE BUT EFFECTIVE TELESCOPE

Galileo's Sketch of Jupiter's Moons

Galileo's most striking discovery was that of four moons orbiting Jupiter...

Sketches of the four moons of Jupiter, as seen by Galileo through his telescope. What he saw are the four larger moons of Jupiter,
now known as Io, Europa, Ganymede and Callisto. The drawing depicts
observations from the time period January 7 to 24, 1610.with January 7-17 in the first column and January 17-24 in the second. Galileo had
considerable difficulty in recognizing the true meaning of what he was
seeing; Callisto often lay outside the (restricted) field of view of
his telescope, Io often lost in Jupiter's glare, and some moon
occasionally disappeared in Jupiter's shadow or behind or in front of
the planet itself.

Galileo named the moons Medicean Stars,
after the ruling Florentine family Medici. This was a move calculated
to improve his chances of moving back to Florence, and it succeeded.
The names used today were coined by Simon Mayr (1573-1624), who in 1612 claimed priority on their discovery. It is possible he saw them in Nov 1609, but without knowing that they were moons rather than distant stars. He also did not announce his alleged discovery or write about it prior to Galileo.

Bibliography:

Debarbat,
S., and Wilson, C. 1989, The Galilean satellites of Jupiter from
Galileo to Cassini, Roemer and Bradley, in The General History of
Astronomy, vol. 2A, eds. R. Taton and C. Wilson, Cambridge University
Press, pps. 144-157.

Sidereus Nuncius, published in 1610, is Galileo's account of his
first astronomical observations using a telescope. He found that the surface of the Moon,
like Earth, is rough and uneven, that the Milky Way and several nebulas are made up of
numerous stars too faint to see individually with the naked eye, and most famously, that
Jupiter has four large satellites.

Over the eight weeks from January 7 to March 2, 1610,
Galileo sketched 64 observations of the positions of these four moons relative to Jupiter.
The following pages reproduce all 64 sketches, along with a modern calculation of the
moons' positions and some brief commentary. Look for the first night that Galileo realized
the moons weren't stars, the night he first saw four moons, not just three, and the only
night he drew a moon that wasn't there.

CLICK ON THE 4 DATED BOXES BELOW TO SEE THE SKETCHES

I've relied on the English translation of Sidereus Nuncius by Albert Van
Helden as well as the edition in the original Latin held by the Linda Hall Library in
Kansas City, MO and made available online by the
Cultural Heritage Language Technologies consortium. I've redrawn each of Galileo's
figures, being careful to preserve both position and relative scale.

I wrote a program to produce the modern diagrams using the methods described in chapter
44 of Jean Meeus's Astronomical Algorithms, second edition. The method was
extended to provide shadow positions in the manner of Sky and Telescope's online Jupiter calculator.
In order of increasing distance from Jupiter, the color-coded moons are Io, Europa, Ganymede
and Callisto.

Each Galileo sketch was scaled to provide the best fit to the positions of the moons.
Galileo had not yet devised a method of rigorously measuring what he saw, and the optics
of his 1610 instrument wouldn't have allowed it in any case, so his sketches are
qualitative, and the scale of the drawings here will vary significantly.

All of the times in the figures are UT. Galileo reported the times of his observations
as a number of hours, and sometimes minutes, after sunset. The times in the figures are
derived from my calculation of the time of sunset in Padua using the method described by Paul Schlyter.

Photo Below is Taken from a Facsimile of Galileo's Sketch Book of Jupiter's Moons by Linda Prince

---------------------------------------------------------------------

Voyager Makes an
Interstellar Discovery

December
23, 2009: The solar system is passing through an
interstellar cloud that physics says should not exist. In
the Dec. 24th issue of Nature, a team of scientists
reveal how NASA's Voyager spacecraft have solved the mystery.

"Using
data from Voyager, we have discovered a strong magnetic field
just outside the solar system," explains lead author
Merav Opher, a NASA Heliophysics Guest Investigator from George
Mason University. "This magnetic field holds the interstellar
cloud together and solves the long-standing puzzle of how
it can exist at all."

Right:
Voyager flies through the outer bounds of the heliosphere
en route to interstellar space. A strong magnetic field reported
by Opher et al in the Dec. 24, 2009, issue of Nature is delineated
in yellow. Image copyright 2009, The American Museum of Natural
History. [larger image]

The
discovery has implications for the future when the solar system
will eventually bump into other, similar clouds in our arm
of the Milky Way galaxy.

Astronomers
call the cloud we're running into now the Local Interstellar
Cloud or "Local Fluff" for short. It's about 30
light years wide and contains a wispy mixture of hydrogen
and helium atoms at a temperature of 6000 C. The existential
mystery of the Fluff has to do with its surroundings. About
10 million years ago, a cluster of supernovas exploded nearby,
creating a giant bubble of million-degree gas. The Fluff is
completely surrounded by this high-pressure supernova exhaust
and should be crushed or dispersed by it.

"The
observed temperature and density of the local cloud do not
provide enough pressure to resist the 'crushing action' of
the hot gas around it," says Opher.

So
how does the Fluff survive? The Voyagers have found an answer.

"Voyager
data show that the Fluff is much more strongly magnetized
than anyone had previously suspected—between 4 and 5 microgauss*,"
says Opher. "This magnetic field can provide the extra
pressure required to resist destruction."

Above:
An artist's concept of the Local Interstellar Cloud, also
known as the "Local Fluff." Credit: Linda Huff (American
Scientist) and Priscilla Frisch (University of Chicago) [more]

NASA's
two Voyager probes have been racing out of the solar system
for more than 30 years. They are now beyond the orbit of Pluto
and on the verge of entering interstellar space—but they are
not there yet.

"The
Voyagers are not actually inside the Local Fluff," says
Opher. "But they are getting close and can sense what
the cloud is like as they approach it."

The
Fluff is held at bay just beyond the edge of the solar system
by the sun's magnetic field, which is inflated by solar wind
into a magnetic bubble more than 10 billion km wide. Called
the "heliosphere," this bubble acts as a shield
that helps protect the inner solar system from galactic cosmic
rays and interstellar clouds. The two Voyagers are located
in the outermost layer of the heliosphere, or "heliosheath,"
where the solar wind is slowed by the pressure of interstellar
gas.

Voyager
1 entered the heliosheath in Dec. 2004; Voyager 2 followed
almost 3 years later in Aug. 2007. These crossings were key
to Opher et al's discovery.

Right:
The anatomy of the heliosphere. Since this illustration was
made, Voyager 2 has joined Voyager 1 inside the heliosheath,
a thick outer layer where the solar wind is slowed by the
pressure of interstellar gas. Credit: NASA/Walt Feimer. [larger
image]

The
size of the heliosphere is determined by a balance of forces:
Solar wind inflates the bubble from the inside while the Local
Fluff compresses it from the outside. Voyager's crossings
into the heliosheath revealed the approximate size of the
heliosphere and, thus, how much pressure the Local Fluff exerts.
A portion of that pressure is magnetic and corresponds to
the ~5 microgauss Opher's team has reported in Nature.

The
fact that the Fluff is strongly magnetized means that other
clouds in the galactic neighborhood could be, too. Eventually,
the solar system will run into some of them, and their strong
magnetic fields could compress the heliosphere even more than
it is compressed now. Additional compression could allow more
cosmic rays to reach the inner solar system, possibly affecting
terrestrial climate and the ability of astronauts to travel
safely through space. On the other hand, astronauts wouldn't
have to travel so far because interstellar space would be
closer than ever. These events would play out on time scales
of tens to hundreds of thousands of years, which is how long
it takes for the solar system to move from one cloud to the
next.

"There
could be interesting times ahead!" says Opher.

To
read the original research, look in the Dec. 24, 2009, issue
of Nature for Opher et al'sarticle, "A strong, highly-tilted
interstellar magnetic field near the Solar System."

*What
is a microgauss? -- A microgauss is one millionth
of a gauss, a unit of magnetic field strength popular
among astronomers and geophysicists. Earth's magnetic
field is about 0.5 gauss or 500,000 microgauss.